Global Solar Radiation Estimation at Presidente Prudente-SP in the years of 1999 to 2007

• Grant number: 11/21092-5
• Support type: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): February 01, 2012
• Effective date (End): December 31, 2012
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Physical Geography
• Principal researcher: José Tadeu Garcia Tommaselli
• Grantee: Vinícius Arthico Demori
• Home Institution: Faculdade de Ciências e Tecnologia (FCT). Universidade Estadual Paulista (UNESP). Campus de Presidente Prudente. Presidente Prudente , SP, Brazil

Abstract

The wide territorial extension of Brazil derails the installation and maintenance of instruments for measuring solar radiation, which makes necessary the development and application of models that are able to estimate reliable and sufficient data for many different activities that use such data. And these, in most cases, are estimated from the Ångstron equation. Based on this model, this project will aim to estimate the global solar radiation at Presidente Prudente-SP, Brazil, using daily data from 1999 to 2007. The solar radiation data will be extracted from the paper tapes of actinograph bi-metallic (Robitsch) daily records at the meteorological station in the Faculty of Science and Technology, UNESP. These tapes will be digitalized, resulting in digital images with x and y coordinates pairs (x = time; y = solar radiation, cal/min.cm²). The daily global solar radiation is the area under the curve of the image. This value will be calculated by computer algorithms. After the acquisition and calculation of the values needed to develop the Ångstron equation will be determined the constants "a" and "b", using linear regression between the values of Rg/Ro (solar radiation/solar radiation on a horizontal surface at the top of atmosphere), as ordered, and n/N (number of hours of sunshine/day length in hours) as abscissa. The slope of the line will be the constant "b" and the linear coefficient, the constant "a". The estimated results are compared to the observed using the Kolmogorov-Smirnov test.